1. Field of the Invention
The present invention relates to integrated semiconductor devices and power supplies for such devices. More particularly, the present invention relates to a half-wave rectifier circuit which may be integrated on the same piece of semiconductor material as the circuitry which it drives and which uses a minimum number of discrete components.
2. The Prior Art
Discrete components half-wave rectifier circuits are well known and are in wide use to power all types of DC circuitry. Recently, packaged power supplies have come into use. Such power supplies reduce the cost of an electronic system in which they are utilized, and often save space, further making packaged systems more economical to produce. Some of these power supplies utilize pre-packaged rectifier subassemblies which contribute to the above-recited economies.
Because of their nature, certain electronic circuits, i.e., those incorporating triacs and SCRs used to control AC power in products such as microwave ovens and other appliances, heater circuits and lighting control circuits, require a circuit connection which is common to one side of the AC power line, usually the neutral side. The total power consumed by such circuits, including triac drives, is usually on the order of less than one watt. DC power for such circuits may be supplied by either a transformer-coupled full wave rectifier or a singe diode half-wave rectifier.
The recent miniaturization revolution has been brought about by introduction of the integrated circuit, which incorporates a plurality of semiconductor devices on the same piece of semiconductor substrate material. Integrated circuit elements have found their way into use in many products; refrigerators, washing machines, microwave ovens and television sets are but a few of the many products which incorporate microprocessors to enhance their functionality. Many, if not most, of these products take power from the AC power supplied to homes and businesses. At power levels in the neighborhood of one watt or less, it becomes economically advantageous to integrate a rectifier or complete power supply onto the same semiconductor substrate as the circuitry it drives.
The provision of integrated components and subassemblies make these products easier and more economical to produce. However, the integration of more than one diode in the configuration necessary to produce a current-driven half-wave rectifier has presented several technical problems due to the nature of both the diode circuit and the nature and architecture of the semiconductor medium onto which more than one of such diodes must be integrated.